package com.monkey.utils;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.Resource;

/**
 * Created by silentwu on 2015/6/24.
 */
public abstract class SpringUtils {

    private static ApplicationContext applicationContext;

    public static void initial(ApplicationContext applicationContext) {
        SpringUtils.applicationContext = applicationContext;
    }

    /**
     * 1. classpath: classpath:com/myapp/config.xml , Loaded from the classpath.
     * 2. file: file:/data/config.xml Loaded as a URL, from the filesystem.
     * 3. http: http://myserver/logo.png Loaded as a URL.
     * 4. (none) /data/config.xml ,Depends on the underlying ApplicationContext.
     *
     * @param location
     * @return
     */
    public static Resource getResource(String location) {
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getResource(location);
    }

    /**
     * 获取对象
     *
     * @param name
     * @return Object 一个以所给名字注册的bean的实例
     * @throws org.springframework.beans.BeansException
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) throws BeansException {
        if (applicationContext == null) {
            return null;
        }
        return (T) applicationContext.getBean(name);
    }

    /**
     * 获取类型为requiredType的对象
     *
     * @param clz
     * @return
     * @throws org.springframework.beans.BeansException
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(Class<T> clz) throws BeansException {
        if (applicationContext == null) {
            return null;
        }
        return (T) applicationContext.getBean(clz);
    }

    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name, Class<T> clz) {
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(name, clz);
    }

    /**
     * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true
     *
     * @param name
     * @return boolean
     */
    public static boolean containsBean(String name) {
        return applicationContext != null && applicationContext.containsBean(name);
    }

    /**
     * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
     * 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
     *
     * @param name
     * @return boolean
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     */
    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
        return applicationContext != null && applicationContext.isSingleton(name);
    }

    /**
     * @param name
     * @return Class 注册对象的类型
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     */
    public static Class<?> getType(String name) throws NoSuchBeanDefinitionException {
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getType(name);
    }

    /**
     * 如果给定的bean名字在bean定义中有别名，则返回这些别名
     *
     * @param name
     * @return
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     */
    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getAliases(name);
    }


}
